Profiling Swallowing Safety and Physiology in People With Huntington's Disease

Dysphagia is prevalent in individuals with Huntington's disease (HD), yet the underlying mechanisms of dysphagia remain unknown. We profiled swallowing safety and physiology in individuals with HD using the validated Penetration-Aspiration Scale (PAS) and the Modified Barium Swallow Impairment Profile (MBSImP).

This retrospective study included 40 adults with HD who underwent videofluoroscopic swallow studies (VFSS) between 2018 and 2024 at Vanderbilt University Medical Center. Trained raters extracted demographics, disease characteristics (duration, United Huntington Disease Rating Scale [UHDRS] Motor Component Total scores, cytosine, adenine, guanine [CAG] repeats), and worst PAS scores from Epic. Two MBSImP-certified clinicians performed duplicate, independent, blinded ratings to obtain overall impairment and severity ratings. Inter- and intra-rater reliability, descriptive statistics, and Spearman's Rho correlations were performed.

Swallowing safety profiles observed were 65% safe, 7.5% penetration, and 27.5% aspiration. 81% of aspirators did so silently. Relationships between PAS scores and disease duration (r_s = 0.336, p = 0.036) and PAS scores and UHDRS motor scores (r_s = 0.382, p = 0.020) were noted. 85% of MBSImP oral phase scores and 97.5% of pharyngeal phase scores had none-to-mild severity, while 15% and 2.5%, respectively, showed moderate severity. No significant correlations were observed between MBSImP scores, demographics, or disease characteristics.

Individuals with HD exhibited greater impairments in swallowing efficiency than in safety, with the oral phase more affected than the pharyngeal. Relationships between swallowing safety and disease severity characteristics in HD suggest these metrics may serve as indicators of swallowing safety impairments, and that further assessment is warranted.